Security Challenges for Public Cloud

Abstract

The integrity of data in cloud storage is sub-ject to skepticism and scrutiny, as data stored in the cloud can easily be corrupted due to the inevitable hardware/software fail-ures and human errors. Therefore, the integrity of cloud data should be verified before any data utilization, such as search or computation over cloud data. The traditional approach for checking data correctness is to retrieve the entire data from the cloud, and then verify data integrity by checking the correctness of signatures or hash values of the entire data. Certainly, this conventional approach is able to successfully check the correct-ness of cloud data. However, the efficiency of using this tradition-al approach on cloud data is in doubt. The main reason is that the size of cloud data is large in general. Downloading the entire cloud data to verify data integrity will cost or even waste user amounts of computation and communication resources, especial-ly when data have been corrupted in the cloud.